^Is the button in the bottom left of the animation editor. You can right click to add new points or delete points to get a more precise or easier to manage collision box. C2 tries to autogenerate them, but it does it oddly sometimes.

Don't use these events. Do Touch then in a sub event check Is flipped then add Else to the sub-event and do the opposite action. This is a common mistake - event 1 sets it to flipped, then event 2 checks if it is flipped (which it is since you just flipped it), and un-flips it!